Electrical contact device



Aug. 3,

O. l. THOMPSON ELECTRICAL CONTACT DEVICE Filed April 28, 1961 @LQ-l 2 Sheets-Sheet 1 Aug. 3, 1965 o. l. THOMPSON 3,199,065

ELECTRICAL CONTACT DEVICE Filed April 28, 1961 a sheets-sheet 2 United States Patent O 3,199,065 ELECTRICAL CONTACT DEVICE rville I. Thompson, Deerfield, Ill., assigner to'De Vry Technical Institute, Inc., Chicago, Ill., a corporation of Illinois Fiied Apr. 28, 1961, Ser. No. 105,225 9 Claims. (Cl. 339-149) The present invention relates to contact devices for electrical apparatus, and more specically it relates to plug in type contact assemblies for interconnecting a plurality of electrical elements.

In the inventors patent application entitled Device for Constructing Electrical Apparatus, Serial No. 41,290, tiled July 7, 1960, now Patent No. 3,085,177, issued April 3, 1963, a board is disclosed which may be utilized directly with components of an electrical circuit to construct that electrical circuit. A plurality of contact members are mounted Ibeneath the surface of a board, and the terminal wires of the electrical elements are plugged into the electrical contact members within the board. A plurality of such electrical circuit elements may have their Wire terminals plugged into a single electrical contact member, thereby interconnecting the electrical circuit elements. This invention is directed to a preferred electrical contact member which is suitable for use with such electrical apparatus constructing devices, and also for other applications requiring the interconnection of electrical terminals.

United States Patent No. 2,922,135 which issued to Hoberg et al., entitled Electrical Pinboard Cross Connecting Device, discloses a female electrical contact member in which a plurality of pairs of prongs extend from a common base member and confront each other. The electrical pin-type terminal is inserted between the prongs and held in position due to the resilience of the prongs. With such an. electrical contact member, the pin-type terminal inserted between the prongs must be limited as to size and the electrical contact cannot be used `over too many cycles or the terminal will not be suihciently securely held in position. Further, the use of confronting prongs for the female contact member provides essentially point contact between the female contact member and the male contact member. The prongs of the female contact member of the Hoberg patent are formed by bending a flat sheet of electrically conducting material into an essentially U-shaped cross-section. Since the contact pressure between the female and male members is solely provided by the resilience of the electrically conducting sheet, any deformation of vthe female -contact member beyond the yield point of the material impairs its effectiveness as an electrical contact. Hence, insertion of a male contact member at a wrong angle will result in permanent damage to the female contact member.

It is, therefore, an object of the present invention to provide an improved female Contact member. Further,

it is an object of the present invention to provide a fe male contact member which is capable of handling male contact elements of varying sizes without damage, and which is capable of withstanding abuse which might occur as a result of the male contact member being inserted at an improper angle. Further, it is an object of the present invention to provide a female contactmember which provides line contact between the male and female contact members rather than essentially point contact.

These and further objects of the present invention will become readily apparent to those skilled in the art from a further consideration of the present disclosure, particularly when viewed in light of the drawings, in which:

FIGURE 1 is a plan view of a female electrical contact tion for the female contact member.

ber 1t) has a trough 14 which is constructed of electrical-v ly insulating rigid material, such as plastic, wood, or the ice member constructed according -to the teachings of the present invention;

FIGURE 2 is a sectional view of the electrical contactmember taken along the line 2 2 of FIGURE 1;

FIGURE 3 is a sectional view of the electrical contact` member taken along the line 3-3 of FIGURE 1;

FIGURE 4 is an end elevational view of a portion of the electrical contact member illustrated in FIGURES 1V through 3 prior to ultimate assembly;

FIGURE 5 is a sectional view of the contact member shown in FIGURES 1 through 3 on the same plane as FIGURE 2 with a male contact member inserted therein; and

FIGURE 6 is a sectional View along a plane similar to that of FIGURE 2 showing a further embodiment of the present invention.

FIGURES 1 through 5 illustrate a preferred construc- This contact memlike. The Vtrough 14 has a pair of parallel walls '16 and 18 and a base 20 normal to the walls 16 and 18. An insert 22 of electrically conducting resilient material is disposed between the walls 16 and 18 of the trough 14.

FIGURE 4 illustrates the insert 22 before it is mounted within the trough 14. The insert 22 is formed of a single at sheet of electrically conducting spring material, such as Phosphor bronze, spring brass or beryllium. The insert 22 has a base 24 which is a rectangular portion with a width approximately equal to the distance between the walls 16 and 18 of the trough 14. On the parallel edges of the base 24 are bends 26 and 2S, and these bends are less than a right angle and form walls 30 and 32l which extend from the base 24. The walls 30 and 32 are thus at an obtuse angle to the base 24. As is clear from FIGURES 1, '2, and 5 the insert 22 is positioned within the trough 14 with the walls 30 and 32 abutting the Walls 16 and 18 of the trough, respectively. Also, the base .24v of the insert abuts the base 20 of the trough. In this manner, spring tension from the insert 22 rigidly holds.

the insert within the trough 14.

The edge of the wall 30 opposite the bend 26 terminates in a bend referred to as a first crimp and designated 34. This first crimp 34 is parallel to the bend 26 adjacent to the base 24 and slightly exceeds 180. The portion 36 at the opposite side of the crimp 34 from the wall 3?, referred to as a return portion, extends toward the wall 30, and must contact the wall 30 when theinsert 22 is assembled in the Vtrough 14. However, in order to minimize the angle through which the sheet of conducting material isbent at the first crimp 34, the return portion 36 is permitted to terminate at a small distance from.

the wall 30 in its unassembled form, and this distance is overcome whenV the insert 22 is inserted into the trough 14. The return portion 36 terminates at its edge oppo.

site the rst crimp 34 in a bend 38 which is parallel to the first crimp 34 but in the opposite direction. The bend 3S is substantially less than 90, and forms a face '40f which is disposed at an acute angle to the wall 30. The end of the face 40 opposite the bend 384 terminates in a bend 42 which is in a direction opposite to the bend 38` and forms a strip 44. The edge of the strip 44 opposite the bend 42 terminates in a second crimp 46 which is parallel to the other bends and rst crimp, and extends through an angle of approximately 180, as does the first crimp. The second crimp 46 also forms a return portion 48 on the side thereof opposite the strip 44, and a support extension 50 extends from a bend 51 at the opposite edge of the return portion 48 from the second crimp 46 and the extension 50 terminates in abutment with the wall 30.

A third crimp 52 is disposed at the edge of the wall 32 opposite the bend 28. and a return portion 54 extends from the side of the third crimp opposite the wall 32. A bend 56 is disposed between the return portion 54 and a second face 58, and a bend 60 is disposed between the second face 5S and a second strip 62. A fourth crimp 64 is disposed at the edge of the second strip 62, and a return portion 66 extends therefrom. A second support extension 68 extends from the return portion 66 through a bend 69 to abut the surface of the wall 32.

FIGURES 1 and 3 indicate a plurality of equally spaced slots 70 along the axis of the insert 22, thereby forming a plurality of equally spaced prongs 72. The slots 7i) extend to the base 24 of the insert 22 and permit each of the prongs 72 to act in an independent manner. As a result, male members of different diameters may be inserted between different pairs of confronting prongs 72 providing firm contact.

From FIGURE 4, which illustrates the insert 22 without the troughv 14, it is to be noted that the wall and first strip 44, are at a small acute angle, and that the wall 32 and second strip 62 are also at approximately the same small acute angle. In the construction set forth in FIGURE 4, this small acute angle is approximately 2. Also, it is to be noted that the second crimp 46 and fourth crimp 64 are very close to each other in the unassembled condition of the `insert 22. Thus, when the insert 22 is inserted into the-trough 14, the first strip 44 yabuts the second strip 62 along its entire length. This fact is clearly illustrated in FIGURE 2. Further, the support extensions 50 and 68 are forced against the inner surfaces of the `Walls 30 and 32, respectively, thereby creating a moment about the crimps 46 and 64 to further force the first strip 44 and second strip 62 into abutment. Sutiicient torque is exerted through the support extensions 50 and 68 to close the second crimp 46 and the fourth crimp 64.v Also, the force exerted on the first and second strips 44 and 62 is suiiicient to close the first crimp 34 and third crimp 52.

The manner of operation of this electrical contact member is best illustrated by considering its action when a male contact member such as a wire terminal, is inserted therein, as set forth in FIGURE 5, the male contact member being designatedv 74. The male contact member 74 first strikes the faces 40 and 5S forcing the two strips 44 and 62 apart.v Insertion of the male contact member 74 also creates a clockwise torque at the location of the third crimp 52 and counterclockwise torque at the location of the first crimp 34. Since the torque applied at `these crimps is in the same direction as the bends forming these crimps, this torque merely transmits the force thereof from the face 40 or 58 to the wall 30 or 32, respectively, since the crimps 34 and 52 are closed and can achieve no further bending. The result is that the counterclockwise torque exerted on the crimp 34 causes the portion of the wall 30 adjacent to the crimp 34 to bend away from the wall 16 of the trough 14, and the clockwise torque exerted on the crimp 52 causes the portion of the wall 32 adjacent to the crimp 52 to bend away from the wall 18 of the trough 14. vIt is to be noted that the bend 42 between the first face 40 and the first strip 44 is also bent in a direction opposite to its permanent set, placing a bend on the first face 40. The same is of course true with regard to the bend 60 between the second face 58 and second strip 62. The bends placed upon the faces 40 and 58 also create a moment forcing the first strip 44 and second strip 62 toward each other tending to maintain line Contact with the male contact member 74 between the two strips.

The first support extension and the second support extension 68 are also bowed against the inner surface of the walls 30 and 32, respectively, thus transmitting torque through the `closed crimps 46 and 64 to the strips 44 and 62. This action also maintains line contact with the male member 74. The fact that the crimps 34, 46, 52, and 64 are closed prevents the force exerted on these crimps from further bending the crimps. This fact means that a substantial force may be applied against these very tight bends without changing the permanent set of the bends. The fact that the bends occur over the relatively long lengths of the support extensions 50 and 68, the faces 40 and 58, and the walls 30 and 32, means that the extent of the deformation is insufficient to materially effect the permanent set of these porions of the insert 22.

FIGURE 6 illustrates a modified form of a female contact member constructed according to the teachings of the present invention. Certain lelements of this contact member are identical to those shown in FIGURES 1 through 5 and bear identical reference numerals. This female contact member has a trough 14 identical to the trough previously described and an insert 22a is disposed therein. The insert 22a has a base 24 and walls 30 and 32 identical to those previously described. At the end of the wall 36 opposite the base 34 is disposed a counterclockwise bend 76 which directly forms a face portion 78. A second counterclockwise bend 80 is disposed between the face 78 and a strip 82. A third counterclockwise bend S4 is disposed between the strip 82 and a support extension S6. It will be recognized that the face 78 is analogous to the face 40 'of the earlier embodiment, and that the strip 82 is analogous to the strip 44 of the earlier embodiment and that the support extension 86 corresponds to the support extension 50 of the earlier embodiment.

In like manner, a clockwise bend 88 is disposed at the edge of the wall 32 opposite the base 24 to form a second face 90. A second clockwise bend 92 is disposed at the edge of the face opposite the bend 88 to form a second strip 94, and a third clockwise bend 96 is disposed at the opposite edge of the strip 94 to form a second support extension 98.`

It will be noted that the structure of FIGURE 6 is essentially the same as the structure previously disclosed with the exception that the crimps 34, 46, 52 and 64 have been omitted. In place of the crimps are relatively sharp bends, 76, 84, 88 and 96. It is clear that when a male contact member, such as the member 74, is inserted between the strips 82 and 94, the above designated bends are all tightened. This construction is therefore not preferable to the one previously disclosed. This construction is, however, a suitable and usable structure due to the fact that the principal bending will occur in the walls 3U and 32, and in the support extensions 86 and 98, as in the previous embodiment. This fact results from the fact that the designated fiat surfaces are relatively long and also the fact that further bending of the bends is more diticult than bending the material originally.

When a permanent set is placed in the electrically conducting sheet, the fibres within the sheet adjacent to the concave surface are placed under compression while the fibres adjacent to the convex surface are placed under tension, and intermediate to these two regions is a region in which the fibres are not placed under either compression or tension. Since the deformation must continue beyond the yield point of the material, it produces a change in the material itself. Thereafter, an attempt to further bend the material requires a larger force for the same displacement.

From the foregoing disclosure, those skilled in the art will readily devise many modifications which are intended to be within the scope of the present invention. Further, many applications of the present invention will become apparent upon investigation and consideration of this disclosure. It is therefore intended that the scope of the present invention be not limited to the foregoing embodiments, but rather only by the appended claims.

The invention claimed is:

1,An electrical contact comprising a sheet of electrically conducting resilient material having a fiat wall, said sheet having a fiat face terminating in parallel opposite sides and disposed at an acute angle to the wall, one ofthe sides of said face being connected to the wall through a bend exten-ding through an angle in excess of 90, said sheet having a flat strip portion -terminating in parallel `opposite sides and disposed approximately parallel to the wall, one of the sides of said strip portion being connected to the side of the face opposite the wall by a bend less than 90, and a normally fiat support extension having parallel sides disposed atan acute angle to the strip portion, one of the sides of the support extension being connected to the strip portion through a bend of greater than 90 and the -other side of the support extension abutting lthe wall, and means defining two parallel fiat surfaces spaced from each other, the fiat wall of the sheet abutting one of the surfaces and the port-ion of the fiat wall .adjacent to the face being free to move relative to said surface, the other surface of said means being adapted to compress a contact member between said surface andthe strip portion.

2. A contact member for an electrical connector comprising a sheet of electrically conducting resilient material having a flat wall, said sheet having a flat face terminating in parallel opposite sides and disposed at an acute angle to the Wall, one of the sides of said face being connected to the Wall through a first bend in a first direction extending through an angle no greater than 90 and a second bend in the opposite direction extending through an angle 4of approximately 180, said second bend being between the wall and the first bend, said sheet having a fiat strip portion terminating in parallel opposite sides and disposed approximately parallel to the wall, one of the sides of said strip portion being connected to the side of the face opposite the wall by a bend in the opposite direction to the first bend extending through an angle less than 90, and la normally fiat support extension having parallel sides disposed at an acute angle to the strip portion, one of the sides of the support extension being connected to the strip portion through a bend in the opposite direction to the first bend of greater than 90 and the other side -of the strip portion abutting the wall.

3. An electrical contact comprising the combination of claim 2 in combination with electrically conducting means structurally :associated with the wall defining a surface parallel to the strip portion and adapted to compress an electrical connector between said surface and the strip portion, and means defining two parallel confronting surfaces disposed at a fixed distance from each other, the sheet being disposed between the surfaces with the fiat wall thereof loosely abutting one surface and the electrically conducting means abutting the other surface.

4. A contact member for an electrical connector comprising a sheet of electrically conducting resilient material having a flat base with parallel sides, a first fiat wall extending from the base at an angle no greater than a right angle, said first Wall being connected .to one side cf the base by a counter-clockwise bend relative to the base, said sheet having a first fiat face terminating in parallel opposite sides and disposed at an acute angle to the wall, one of the sides of said tace being connected to the wall through a second bend in a counter-clockwise direction relative to the wall and extending through an angle in excess of 90 degrees, said sheet having a first fiat strip portion terminating in parallel opposite sides and disposed approximately parallel to .the first wall, one of the sides of said first strip portion being connected to the side of the first face opposite the first wall by a bend in the counterclockwise direction relative to the first face less than 90 degrees, a first normally fia-t support extension having parallel sides disposed at an acute angle to the first strip portion, one 4of the sides of .the first support extension being connected to the strip portion through a bend extending in a counter-clockwise direction relative to .the rst strip portion through an angle greater than degrees andV sides of the second face being connected to the second wall through a clockwise bend relative to the second wall extending through an angle in excess of 90 degrees, s-aid sheet having a second flat strip portion terminating in parallel o-pposite sides and disposed .approximately parallel to the second wall, one of the sides-of said second strip portion being connected to the side of the second face opposite the second Wall by a clockwise bend relativev to the second face of less than 90 degrees, and a secondl normally fiat support extension having parallel sldes dis.

posed at an acute angle to the second strip portion, one of the sides of the second support extension being connected to the second strip portion through a clockwise bend relative to the second strip portion of greater than 90 degrees and the other side of the second support extension abutting the second wall, the first and second strip portions confront-ing each other.

S. An electrical contact comprising the combination of claim 4 in combination with means defining a trough having parallel confronting walls, the sheet of electrically conducting material being disposed within the trough with the first and second walls of the sheet in abutment with the walls of the trough and the rst and second stripportions of the sheet in abutment with each other.

6. A contact member for an electrical connector cornprising a sheet of electrically conducting resilient mate- -rial having a flat wall, said sheet hav-ing a fiat face terminating in parallel opposite sides and disposed at an acute angle to the wall, one of the sides of said face being connected to the wall through a first bend in a first direction relative to the wall extending through an Vangle in excess of 90 degrees, said sheet having a fiat strip portion terminating in parallel opposite sides and disposed approximately parallel t-o the Wall, one of the sides of said strip portion being connected to the side of the face opposite the wall by a second bend in the same direction as the first bend relative to the face -of less than 90 degrees, and a normally fiat support extension having parallel sides disposed at an acute angle to the strip portion, one of the sides of the support extension being connected to the strip portion through a third bend in the same direction as the first and second bends relative to the strip portion of approximately degrees and a fourth bend in the direction opposite to the third bend relative to the strip portion disposed between the third bend and the support extension of less than 90 degrees, the other side of the support extension abut-ting the wall.

7. An electrical contact comprising the elements of claim 6 in -combination with electrically conducting means strnctually associated wit-h the wall defining a surface parallel vto the strip portion and a-dapted to compress an electrical connector between said surface and the strip portion, and means defining two parallel surfaces disposed at a fixed distance from each other, the sheet being disposed between the surfaces with lthe fiat wall thereof loosely abutting one surface and the electrically conducting means Iabutting the other surface.

8. A contact member for an electrical connector comprising a sheet of electrically conducting material having a fia-t base with parallel sides, a first fiat wall having parallel sides, one of said sides being connected to one of the sides of the base through a first counter-clockwise bend relative to the base, said sheet having a first flat face terminating in parallel opposite sides and disposed at an .acute angle to the first wall, one of the sides of said face being -connected to the first wall through a second counterclockwise bend relative .to the tirst Wall extending through an angle of approximately 180 degrees and -a third clockwise bend rel-at-ive to the first Wall extending through an angle no greater than 90 degrees, said third bend being disposed between the first fiat face and .the second bend, said sheet having a first flat strip portion terminating in parallel opposite sides and disposed approximately parallel to the rst wall, one of .the sides of said strip portion being connected to the side of the first face remote from the iirst wall by a fourth counter-clockwise bend relative to the first face less than 90 degrees, a normally at first support extension having parallel opposite sides disposed at an acute angle to the first strip portion, one of thesides of the first support extension being connected to the first strip portion through a fifth counter-clockwise bend relative to the first support extension of approximately 180 degrees and a sixth clockwise bend relative to the first strip portion less than 90 degrees, the first support extension having the side thereof remote from the iirst strip portion in abutment with the first wall, said sheet having a second fiat wall with opposite parallel sides, one of the sides of the second wall being connected to the side of the base remote from the irst bend through a seventh clockwise bend relative to the base, said sheet having a second flat face terminating in parallel opposite sides and disposed at an actue angle to the second wall, one of the sides of the second face being connected to the second wall through an eighth clockwise bend relative .to the second wall extending through an angle of approximately 180 degrees and a ninth counterclockwise bend relative to the second wall extending through an angle no greater than 90 degrees, said eighth bend being disposed between the second wall and the ninth bend, said sheet having a second fiat strip portion terminating in parallel opposite sides and disposed approximately parallel to the second wall, one of the sides of said second strip portion being connected to the side of the second face remote from the second wall by a tenth clockwise bend relative to the second face of less than degrees, and a normally at second support extension having parallel opposite sides disposed at an acute angle to the second strip portion, one of the sides of the second support extension being connected to the second strip portion through an eleventh clockwise bend relative to the second strip portion extending through an angle of approximately degrees and a twelfth counterclockwise bend relative to .the second strip portion ex- -tending through an angle less than 90 degrees and disposed between the second support extension and the eleventh bend, and the other side of the second support extension abut-ting the second Wall.

9. An electrical contact comprising the elements of claim 8 in combination with means defining a trough with parallel walls and a base perpendicular thereto, the base of the sheet abutting the base of the trough defining means and the walls of the sheet abutting the Walls of the trough delining means.

References Cited by the Examiner UNITED STATES PATENTS 1,231,417 A6/17 Nero 339-259 1,626,692 5/27 Rawling 339-262 X 1,780,413 11/30 Williams 339--258 X 1,841,736 1/32 Jones 339-217 2,922,135 1/60 Hobelg et al 339-18 3,047,831 7/62 Majewski 339-258 X 3,076,953 2/63 Sloop 339-259 3,114,586 12/63 Albert 339-258 X FOREIGN PATENTS 380,3 62 5/40 Italy.

OTHER REFERENCES Y DeIur-Amsco Corp. Electronic Design (publication) page 2l, Mar. 15, 1956.

JOSEPH D. SEERS, Primary Examiner. 

1. AN ELECTRICAL CONTACT COMPRISING A SHEET OF ELECTRICALLY CONDUCTING RESILIENT MATERIAL HAVING A FLAT WALL, SAID SHEET HAVING A FLAT FACE TERMINATING IN PARALLEL OPPOSITE SIDES AND DISPOSED AT AN ACUTE ANGLE TO THE WALL, ONE OF THE SIDES OF SAID FACE BEING CONNECTED TO THE WALL THROUGH A BEND EXTENDING THROUGH AN ANGLE IN EXCESS OF 90*, SAID SHEET HAVING A FLAT STRIP PORTION TERMINATING IN PARALLEL OPPOSITE SIDES AND DISPOSED APPROXIMATELY PARALLEL TO THE WALL, ONE OF THE SIDES OF SAID STRIP PORTION BEING CONNECTED TO THE SIDE OF THE FACE OPPOSITE THE WALL BY A BEND LESS THAN 90*, AND A NORMALLY FLAT SUPPORT EXTENSION HAVING PARALLEL SIDES DISPOSED AT AN ACUTE ANGLE TO THE STRIP PORTION, ONE OF THE SIDES OF THE SUPPORT EXTENSION BEING CONNECTED TO THE STRIP PORTION THROUGH A BEND OF GREATER THAN 90* AND THE OTHER SIDE OF THE SUPPORT EXTENSION ABUTTING THE WALL, AND MEANS DEFINING TWO PARALLEL FLAT SURFACES SPACED FROM EACH OTHER, THE FLAT WALL OF THE SHEET ABUTTING ONE OF THE SURFACES AND THE PORTION OF THE FLAT WALL ADJACENT TO THE FACE BEING FREE TO MOVE RELATIVE TO SAID SURFACE, THE OTHER SURFACE OF SAID MEANS BEING ADAPTED TO COMPRESS A CONTACT MEMBER BETWEEN SAID SURFACE AND THE STRIP PORTION. 